Because their good light transparency, wide band gap of 3.6 eV at room temperature (RT), and high chemical stability, tin oxide (SnO2) layers, films, or coatings find multiple applications in transparent electrodes, panel displays, heat reflection coatings, heterojunction solar-cells, thermal layers protecting widescreens, and gas sensors. These applications require conducting layers with variable electrical and optical properties that can be tuned to the requirements of specific applications.
The electrical properties of current, undoped polycrystalline tin oxide layers or films are usually very poor. Typical mobilities of undoped polycrystalline tin oxide layers deposited on glass are not more than 35 cm2/Vs with electron concentrations being in excess of 1019 cm−3, respectively. Thus, there is a need for conductive tin oxide layers or coatings with improved electrical properties.